In a statement, President Obama said he is "very pleased that Sarah Shourd has been released by the Iranian government, and will soon be united with her family."

All Americans join with her courageous mother and family in celebrating her long-awaited return home. We are grateful to the Swiss, the Sultanate of Oman, and other friends and allies around the world who have worked tirelessly and admirably over the past several months to bring about this joyous reunion.

While Sarah has been released, Shane Bauer and Josh Fattal remain prisoners in Iran who have committed no crime. We remain hopeful that Iran will demonstrate renewed compassion by ensuring the return of Shane, Josh and all the other missing or detained Americans in Iran. We salute the courage and strength of the Shourd, Bauer, and Fattal families, who have endured the unimaginable absence of their loved ones. We have gained strength from their resolve, and will continue do everything we can to secure the release of their loved ones.

Secretary of State Hillary Clinton also issued a statement today:

I welcome Sarah Shourd’s release from detention in Iran, and am pleased that she will soon be reunited with her family. I appreciate the efforts of all those who have worked for her release, in particular the Swiss Protecting Power in Tehran, the Omani Government, and the many other world leaders who have raised this case and the cases of other detained or missing American citizens. Sarah’s fiance Shane Bauer, Joshua Fattal, and other U.S. citizens remain detained or missing in Iran. We urge Iranian authorities to extend the same consideration to them by resolving their cases without delay and allowing them to immediately return to their families.

Shourd, Bauer and Fattal were detained on the border between Iran and Iraq while hiking in July, 2009, arrested and charged with spying. Although Shourd is being let go, an Iranian news agency says Bauer and Fattal's detentions have been extended for two more months. The families of the hikers, and the U.S. urge their release; the families have detailed the hikers' story on Facebook and a support website.

The hikers have a supporter in Professor Akbar Ahmed, chair of American University's Islamic Studies department. He wrote a lengthy plea last month to Iran's Supreme Leader, Grand Ayatollah Khamenei:

As someone dedicated to helping alleviate the suffering of all humanity, whatever their cultural or religious background, I am concerned about the mental and physical well-being of these young people. All are at risk for permanent psychological damage due to their isolation in solitary confinement. They cannot speak Farsi, apart from requesting to be led to the bathroom blindfolded.

For over a year Sarah has lived alone in a prison cell for 23 hours a day. She also may have cancer. Sarah has a precancerous cervix, which requires treatment every three months. She has been taken out of prison once for testing, but the results have not been released. In addition, Sarah has discovered a lump in her breast which demands immediate attention. Besides being potentially afflicted with cancer at such a young age, Sarah is also clinically depressed. Shane has severe stomach problems, which could include hemorrhaging.

Update at 10:45 a.m. ET: According to the Associated Press, Iran released an American woman on a bail of $500,000 Tuesday, but authorities said they were not considering the immediate release of two companions arrested with her.

The announcement came days after conflicting statements by Iranian authorities on whether Sarah Shourd would be freed as the process was complicated by political feuds among the leadership and questions over how a payment could be made for her freedom without violating international sanctions.

The English-language Press TV reported that Shourd, 32, had been released "on a bail of $500,000" but did not give more details. Iran's judiciary, meanwhile, issued a statement saying the "pretrial detention" of the two American men - Shane Bauer and Josh Fattal - has been extended for two more months.

Her family had said it was having difficulty raising the money. However, Tehran's chief prosecutor Abbas Jafari Dowlatabadi said later that the bail had been paid to an Iranian bank in Muscat, Oman.

"The judge issued the release order and Ms. Shourd was simply set free and she can leave Iran if she wants to," Dowlatabadi told Press TV.

Shourd's lawyer, Masoud Shafiei, said he had no information about her departure route or any details about bail.

He later was quoted by the state news agency IRNA as saying Shourd planned to travel to Oman where her mother already was waiting for her, but that could not be confirmed and there were conflicting reports that she would go to the Qatari capital of Doha.